Coroner Terry Ryan is set to hear from 27 witnesses about the 1973 attack during a two-week sitting in the Coroner’s Court in Brisbane from Monday.

It was 2am on March 8 when two drums of fuel were thrown into the downstairs foyer of the bustling nightclub in Brisbane’s Fortitude Valley and set alight.

More than 60 patrons and staff tried frantically to escape as air conditioning vents acted as chimneys, pouring black smoke into the club.

There was a single fire extinguisher, a locked hose and an emergency exit blocked by oil-filled drums, making escape slippery and dangerous, a pre-inquest hearing was told earlier.

Survivors smashed windows to scramble to neighbouring roofs, but not everyone made it out alive.

Fifteen people succumbed to deadly smoke, with autopsies confirming their death from carbon monoxide poisoning.

Two men – John Andrew Stuart and James Richard Finch – were convicted of murder over the crime and sentenced to life in prison.

Stuart died in 1979 and Finch – who had been due to give evidence in the inquest – died this year in the UK where he had been deported after serving 15 years.

Despite the two men being jailed for murder, the full extent of the circumstances causing the deaths had never been “satisfactorily established”, the earlier hearing was told.

The inquest would hear the focus of the police investigation in the aftermath “was not directed at finding all of the people responsible”, counsel assisting Stephen Keim said.

“The available evidence …. raises concerns that Finch and Stuart were not the only actors involved in those fatal events,” he added.

“These concerns extend to fears that a broader group of persons, including possibly police offices themselves, had some role in planning the attack on the nightclub.”

The new inquest was ordered after the firebombing was mentioned in a trial in which Vincent O’Dempsey and Garry Dubois were convicted over the deaths of Barbara McCulkin and her two daughters in January 1974.

That trial was told the killings may have been motivated over fears Ms McCulkin would try to implicate O’Dempsey in the firebombing.

O’Dempsey is expected to be a key witness at the inquest, and the coroner can compel him to answer questions.

Dubois – who had been scheduled to give evidence during a sitting later this year – was found dead in his cell at Maryborough Correctional Centre earlier this month.

One expected witness is Donna Phillips, one of the few remaining survivors, who was working the club’s counter that night.

The Whiskey Au Go Go attack was Australia’s worst mass murder until the 1996 Port Arthur massacre.